Instructions:Read each
question carefully before selecting the BEST answer. Provide specific and
detailed answers to essay questions. Use GEOLOGIC VOCABULARY where
APPLICABLE!USE AN 882 SCANTRON TO
RECORD YOUR ANSWERS FOR THE FOLLOWING MULTIPLE CHOICE AND T/F QUESTIONS.
TURN IN YOUR SCANTRON AND ANSWER SHEET ONLY!

True = A / False = B

1.A Half life is
the number of atoms that decay per unit of time.

2.Radiometric dating means placing events in their proper sequence.

3.After four half-lives there is no longer any of the original radioactive
material remaining.

4.Inclusions are pieces of one rock contained within another.

5.The
radioactive isotope, potassium-40, has Argon-40 as a daughter product.

6.The percentage of radioactive atoms that decay during one half-life will
change.

8.In reference to the geologic time scale, periods are divided into smaller
time units called epochs.

9.It is usually not possible to obtain an accurate radiometric date from a
sample of detrital sedimentary rock.

10.Coal swamps are associated with the Pennsylvanian period.

11.The geologic time scale was originally constructed by scientists with the
aid of numerical dates, because radioactivity had already been discovered.

12.We are now living in the Cenozoic era.

13.James Hutton's
principle of uniformity states that "the past is the key to the present."

14.Probably the single most characteristic feature of the Phanerozoic is its
great abundance of fossil evidence.

15.The law of superposition is used in relative dating.

16.In regards to
cross-cutting relationships, if rock B cross-cuts rock A, then A is younger than
B.

17.Any interval
of geologic time not represented by strata in a particular area is a hiatus.

18.
Key/index/marker beds are particularly distinctive rock units that allow
identification of the same unit in different areas.

19.Guide/Index
fossils have a wide geographic range and short time of existence.

Multiple Choice:

20.The forces and processes that can be observed shaping our present day
landscapes have also operated in the geologic past. The preceding statement
refers to

a.uniformitarianism.

b.catastrophism.

c.Aristotle's hypothesis.

d.Ussher's premise.

e.none of these

21.The principle
of superposition states that

a.sediments are
deposited as essentially horizontal layers

b.the present is
the key to the past

c.undisturbed
sedimentary layers get progressively younger from bottom to top

d.a fault that
cuts a sedimentary rock is younger than the rock

22.By applying the law of superposition _______ dates can be determined.

a.conventional

b.radiometric

c.relative

d.isotopic

e.both relative and radiometric

23.The era of "ancient life" is the _______ era.

a.Cenozoic

b.Precambrian

c.Neolithic

d.Mesozoic

e.none of these

24.A geologic
formation is a series of rock layers that .

a.can be
recognized and mapped as a distinctive unit

b.has
approximately the same physical properties

c.contains the
same assemblage of fossils

d.has all of
these properties

25.The statement "The present is the key to the past" relates to

a.Catastrophism.

b.uniformitarianism.

c.Aristotle's hypothesis.

d.Tarbuck's theory.

e.none of these

26.The subdivision of the geologic time scale that represents the longest
time span is called a(n)

a.Epoch b. Era. c. period.
d. stage.

27.Which one of the following represents the smallest expanse of time?

a.Mesozoic

b.Cenozoic

c.Precambrian

d.Paleozoic

28.Who is credited with formulating the doctrine of uniformitarianism?

a.Aristotle

b.Lyell

c.Hutton

d.Powell

e.Playfair

29.About 85 percent of geologic time is represented by the time span often
called the

a.Paleozoic.

b.Stone Age.

c.Precambrian.

d.Cretaceous.

e.Ordovician.

30.The age of Earth is about

a.2 billion years.

b.4.5 million years.

c.16 million years.

d.4.5 billion years.

e.195 million years.

31.The oldest
rocks on Earth are approximately years old.

a.4 thousand
b. 4 million c. 4 billion d. 4 trillion

32.Abundant fossil evidence did not appear in the geologic record until
about

a.5 billion years ago.

b.6 million years ago.

c.600 million years ago.

d.300 million years ago.

e.3 billion years ago.

33.Of five undeformed horizontal beds of sedimentary rock, we can say that

a.the top layer is oldest.

b.the lowest layer is oldest.

c.the third layer from the bottom is older than the second layer from the
bottom.

d.there is no way of knowing which layer is oldest.

34.An unconformity is

a.a layer of sedimentary rock.

b.a gap in the rock record.

c.A layer of rock with very unusual fossils.

d.a period of
erosion or non-deposition

e.Either b or d.

f.All of the
above.

35.A
disconformity occurs where:

a.the beds are
parallel above and below the unconformable contact

b.the beds above
and below the unconformable contact are at angles to one another

c.sedimentary
rocks overlie massive crystalline rocks

d.all of the
above

36.A
nonconformity closely resembles:
a. fault contact
b. an intrusive contact
c. a soil on its parent rock
d. all of the above

37.Relative time
tells us how long ago an event took place

a.True

b.False

38.Fossils which denote particular short periods of time in the geologic
past are termed

a.Environmental indicators.

b.fossil discriminators.

c.Huttonian fossils.

d.Index or guide fossils.

e.none of these

39.The principle
of fossil succession states that:
a. the same sequence of life forms repeats over and over
b. there has been a change in life forms through time
c. that different assemblages of fossils indicate different geologic
ages
d. answers b. and c.

40.In order to match rocks of similar age in different regions or to
demonstrate age equivalency of rock units, geologists use

a.Lateral tracing

b.Radiometric dating

c.Fossils.

d.sequence of beds.

e.All of these.

f.Similarity of rock type.

g.None of these.

41.Which of the
following is used by geologists to determine the relative ages in a rock
sequence?
a. stratigraphy
b. fossils
c. cross-cutting relations
d. all of these

42.Placing
geologic events in sequential order as determined by their position in the rock
record is called:
a. absolute dating
b. uniformitarianism
c. relative dating
d. correlation
e. historical dating

43.Which one of the following lists places the division of geologic time in
order from shortest to longest?

a.era, period, epoch

b.epoch, period, era

c.period, epoch, era

d.epoch, era, period

e.none of these

44.About what percent of geologic time is represented by written, recorded
human history?

a.Less than 0.01%

b.Approximately 1%

c.Approximately 10%

d.Approximately 100%

e.none of these

45.In undisturbed
sedimentary deposits, the youngest beds:
a. are water beds
b. are on the top
c. are on the bottom
d. could be answers b. or c.

46.The principle
of original horizontality states that:

a.in most cases
sedimentary beds are deposited as horizontal units

b.in rare cases,
horizontality of rock layers occurs.

c.in most cases,
if the beds are inclined, this tilting occurred after the beds were deposited

d.answers a. and
c.

47.Which of the following is related to relative dating?

a.cross-cutting

b.inclusions

c.superposition

d.all of these

e.both inclusions and superposition

48.When tilted or folded sedimentary rocks are overlain by more flat-lying
strata a _______ is said to exist.

a.disconformity

b.angular unconformity

c.nonconformity

d.conformity

e.none of these

49.A layer of sandstone is in contact with a mass of granite. The sandstone
contains small pieces of the granite. Which rock is older?

a.sandstone

b.granite

c.both are the same age

d.it is not possible to determine which is older from the information
provided.

50.Which relative dating principle is illustrated in the preceding question?

a.cross-cutting

b.original horizontality

c.inclusions

d.superposition

e.none of the above

51.An undeformed sedimentary layer is _______ than the layer above and
_______ than the layer below.

a.older, younger

b.younger, older

c.younger, younger

d.older, older

52.Which of the
following processes removes carbon dioxide from the atmosphere?

a.photosynthesis

b.volcanic
eruptions

c.weathering of
organic carbon

d.all of these

53.Assume that you have just examined several flat-lying sedimentary layers.
After much study you determine that there is a considerable span of time for
which no sedimentary rock layer exists at this site. You have just discovered
a(n)

a.angular unconformity.

b.series of conformable strata.

c.disconformity.

d.example of cross-cutting relationships.

54.A worm would stand a poor chance of being fossilized because

a.worms have been rare during the geologic past.

b.worms have no hard parts.

c.worms contain no carbon-14.

d.all of these

e.none of these

55.The era known as the "age of mammals" or “recent life” is the

a.Precambrian.

b.Paleozoic

c.Cenozoic

d.Devonian

e.Silurian

56.What era is sometimes called the "age of dinosaurs"?

a.Pleistocene

b.Cenozoic

c.Cretaceous

d.Mesozoic

e.none of these

57.The oldest
rock in the Grand Canyon is the .

a.Bright Angel
Shale

b.Tapeats
Sandstone

c.Vishnu Schist

d.Coconino
Sandstone

58.Radioactive
decay:
a. produces heat
b. produces a transformation from one element to another
c. answers a. and b.
d. cannot be used to date rocks because the decay rate is not constant

59.Radioactive
dates are based on:
a. the ratio of unstable parent material and stable daughter product
present in asample
b. measuring the amount of unstable isotopes present
c. measuring the number of atoms that decay per unit time
d. none of these

60.Half life:
a. is the time necessary for one half of the parent material to decay
b. times can be very short or very long
c. times are constant for a given element
d. all of the above

62.Radioactive
carbon dates are useful for the past:
a. 5000 years
b. 50,000 years
c. 70,000 years
d. none of the above

63.One type of radioactive decay involves the capture of an electron by a
nucleus. When this occurs

a.the atomic number increases by 1.

b.the atomic number decreases by 1.

c.the mass number increases by 1.

d.the atomic number and the mass number both increase by 1.

e.the atomic number decreases by 1 and the mass number increases by 1.

64.An alpha particle consists of

a.one electron.

b.two electrons and two neutrons.

c.two protons and two neutrons.

d.either b. or c.

e.none of these

65.When an alpha particle is emitted, how do the mass number and atomic
number change, if at all?

a.mass number 4 less, atomic number 2 less

b.mass number 2 less, atomic number 2 less

c.mass number 4 less, atomic number unchanged

d.mass number 4 less, atomic number 2 higher

e.none of these

66.When potassium-40 decays to argon-40, it does so by means of

a.beta particle emission.

b.electron capture.

c.alpha particle emission.

d.both beta particle emission and electron capture.

e.both electron capture and alpha particle emission.

67.When seven-eighths (7/8) of a radioactive isotope has decayed to become
the stable daughter product, _______ half-lives have elapsed.

a.one

b.two

c.three

d.four

e.none of these

68.Assume that the half-life of a particular radioactive isotope is 10,000
years. Laboratory analysis shows that the ratio of radioactive parent to stable
daughter product in a sample is 1:7. In other words, there is one parent isotope
for every 7 daughter isotopes. What is the age of the sample?

a.1428.6 years

b.10,000 years

c.20,000 years

d.30,000 years

e.none of these

69.Which of the
following materials might be dated using carbon-14?

a.sandstone
b. wood c. iron ore d. granite

70.If a rock is
heated during metamorphism and the parent atoms migrate out of a mineral that is
subsequently radiometrically dated, an inaccurate date will be obtained. This
date will be the actual date.
a. younger than
b. older than
c. the same as
d. it cannot be determined
e. none of these

71.What is being
measured in radiometric dating?
a. the time when the radioactive isotope formed
b. the time of crystallization of a mineral containing an isotope
c. the amount of the parent isotope only
d. when the dated mineral became part of a sedimentary rock
e. when the stable daughter isotope was formed

72.If a
radioactive element has a half-life of 4 million years, the amount of parent
material remaining after 16 million years of decay will be what fraction of the
original amount?
a. 1/32 b. 1/16 c. 1/8 d. 1/4 e. ˝

73.How many
half-lives are required to yield a mineral with 625 atoms of U238 and 19,375
atoms of Pb206?
a.4 b.5 c.6 d.8 e. 10

74.Absolute time:
a. gives a non-specific date to an object
b. gives a specific date to an object
c. is only useful if fossils are present
d. only gives the sequence in which events have taken place

Refer to the following
geologic cross section for the following 4 questions. Units A, B, C, D, and F
are sedimentary rocks. Unit E is an igneous rock.

76.When did the
faulting occur?

a.after
deposition of unit A

b.after
deposition of unit C and before deposition of unit B

c.after
deposition of unit F and before deposition of unit C

d.cannot be
determined from the information given

77.What event
happened most recently?

a.erosion of
part of unit C

b.faulting

c.deposition of
unit C

d.deposition of
unit F

78.What type of
rock is unit E?

a.a dike

b.a sill

c.a lava flow

d.answers b. and
c.

e.answers a. and
c.

79.Which is the
oldest unit?
a. unit A b. unit C c. unit E d. unit F

Use the answer sheet
provided in class for the following questions and relative dating problem(s).

80.A series of intersecting dikes or faults may be placed in proper sequence
or order by using the principle of ____________.

81.When one rock mass contains fragments of an adjacent rock mass, we know
the adjacent rock mass must be older. The fragments used for relative dating in
this situation are generally known as ____________.

82.An unconformity in which the strata on either side are essentially
parallel is termed a (n) ____________.

83.An unconformity in which tilted or folded strata are overlain by more
flat-laying layers is known as a (n) _____________ unconformity.

84.What is the
name of a Phanerozoic era that means ancient life?

85.The principle of ____________ states that fossil organisms succeed one
another in a definite and determinable order and that a time period can be
recognized by its fossil content.

86.Dinosaurs lived during the ____________ era.

87.Fossils used for matching rocks of the same age are called ____________.

88."This dike is 10 million years old." The preceding statement is an
example of a (n) ___________ date. Use the terms that you have been learning in
class!

89.The phrase, "The present is the key to the past," refers to the doctrine
of ____________.

90.The remains or
traces of prehistoric life are called ____________.

91.____________ dating occurs when events are placed in their proper
sequence or order without knowing their numerical ages.

92.For a
radioactive isotope like U-235, what does the 235 indicate?

93.Give the mass
number of the naturally produced, radioactive carbon isotope.

94.In an un-deformed sequence of sedimentary rocks, each bed is older than
the one above and younger than the one below. The preceding is a statement of
the principle of ____________.

95.What general
term denotes a buried erosional surface?

96.Fossil A Ranges in Age from the Mississippian to the Pennsylvanian,
Fossil B Ranges in age from the Devonian to the Permian, and Fossil C ranges in
age from the Permian to the Pennsylvanian. In what period/sub-period (whichever
represents the smaller increment of time) did all three fossils exist at the
same time?